Directional gyroscope



April 1, 1952 M. H. AXLER 2,590,837

DIRECTIONAL GYROSCOPE Filed Oct. 3, 1944 2 SHEETS-SHEET 1 INVENTOR.

MYER H- AXL ER ATTO/QNEY 2 SHEETS-SHEET 2 Fild Oct. .5, 1944 INVEWTOR. MEYER 7- -AXL.ER

A I OENEY Patented Apr. 1, 1952 UNITED STATES rarer Fries DIRECTIONAL GYR-OSCOPE Meyer- H. drier, United States Army, Eronr, N. Y. Application October 3, 1944, Serial No. 556,945

1i Claims. 1

This invention relates to direction gyroscopes, and, more particularly, is concerned with a novel means for counteracting the precessional force of such compasses.

I have noticed that the precessional effect varies from directional gyroscope to directional gyroscope as well as with the setting of any given directional gyroscope. At present, constant corrections are made to compensate for the cumulative effect of precession over a period of time. However, these corrections are at best approximate and quite often cause serious navigational errors.

Attempts have heretofore been made to prevent precession, but the mechanisms employed for this purpose have been complicated. and delicate, expensive to manufacture and install, and have required much attention, as well a reconstitution of the directional gyroscope mechanism to enable the precessional correcting means to be used with the same.

It is, therefore, an object of the present invention to provide a directional gyroscope embodying precession counteracting means of the character described which, due to a novel principle of operation, comprises relatively few and simple parts, is rugged and compact in construction and relatively inexpensive to manufacture, can be installed easily on a directional gyroscope without fundamentally altering the construction of the latter, and which can be adjusted readily and quickly to suit the individual characteristics of any directional gyroscope.

Other objects of this invention will in, part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements, and arrangement of parts which will be exemplilied in the construction hereinafter described, and of which the scope of application will be indicated in the claims.

In the accompanying drawings, in which is shown one of the various possible embodiments of this invention,

Fig. 1 is a partially schematic, vertical sectional View through a directional gyroscope embodying my invention;

Fig. 2 is a sectional view taken substantially along the line 2-2 ofFig. l; and

Figs. 3 and 4 are enlarged sectional views taken substantially along the line 3 -.-3 i4, respectively, of Fig. 1.

Referring now to the drawings, I have there shown a directional gyroscope l9 which may be of any conventional construction and which, by way of example, comprises an air-ti ht housing i2 in which there is provided a gyroscope rotor l4. Said rotor is spun by a jet of air i6 issuing from a nozzle iii and impinging upon small buckets or vanes 2i? disposed around the periphery of the rotor. The rotor is mounted on an axle (not shown) whose opposite ends are journalled by anti-friction bearings in a horizontal gimbal ring 22. Said gimbal ring is journalled by anti-friction bearings in a vertical gimbal ring 24 which may carry an annular strip 23 on which headings are printed and which can be viewed through a pellucid pane (not shown) in the side walls of the housing l2.

The vertical gimbal ring is suitably mounted on upper and lower bearings for rotation about a vertical axis. The upper bearing comprises a sleeve secured to the vertical gimbal ring 2% and receiving a spindle Z 8 pendent from the upper wall of the housing i2. lower bearing includes a pin depending from the bottom or" the vertical gimbal ring it and received in a sleeve 32 carried on the bottom wall of the hou ing. Suitable anti-friction bearings may be in cluded in both or" these upper and lowervertical rotatable supports for the vertical gimbal ring.

The directional gyroscope just described is wholly conventional and can be replaced with any other directional gyroscope of well known design without departing fr m the spirit of my invention.

As mentioned ea" I have noticed that directional gyroscopes precess, that is, turn about a vertical axis. changes the heading indicated by the inst- Jment. Such precession varies considerably with oifierent directional gyroscopes and cannot be predicted. i believe that the same is due to friction in the bearings, although it will be understood that this is merely offered by way of suggested explanation and has no effect upon the mechanism forming the subject matter of the instant invention. To correct for this precessicnal effect, in accordance with the instant invention I provide a device forcounteracting the precessional torque in a highly simple yet novel manner.

Said device basically includes a mechanism, stationarlly mounted a series of projections and spaces formed, -for example, by roughening the surface of a disc, by employing buckets or by using a set of vanes. The projections are spaced uniformly and closely enough together, with regard to the diameter of the stream, so that a change in the relative angular positions of the stream and said means will not change the torque developed thereby.

More specifically, said precession counteracting device includes a rigid horizontal disc 3% permanently-and igidly secured, for example, by a set screw (not shown), to the sleeve so that said disc will turn about a vertical axis with the gimbal mounting comprising the two giinbal rings 22, 24, and will, more particularly, turn about a vertical axiswith the vertical gimbal ring 24. Said disc is provided with a large number of uniformly and closely spaced, radia vertical vanes 36.

A fluid stream is directed against said vanes by either one of a pair of spaced nozzles 38, '18 which are furnished with a gaseous medium, for example, air under pressure, from a suitable source of compressed air, such as the supply conduit 42. These nozzles are mounted stationarily on the housing l2 and are so disposed as to direct the jets of air emerging therefrom an angle to the vanes 36 such that a horizontal torque is developed about the vertical axis of rotation of the gimbal mounting. In this manner, a jet issuing from either nozzle under a specified degree of pressure will apply a predetermined horizontal torque to the sleeve 26. The nozzles 38, are so arranged relative to the vanes that they will produce opposite torques, i. e., as viewed from Fig. 2, an air stream emerging from the nozzle 38 will produce a clockwise torque and an air stream issuing from the nozzle 40 a counter-clockwise torque. The reason for this will shortly be apparent.

It will be appreciated that the torque created by one of said nozzles will add to the precessional torque and that created by the other nozzle will oppose the same. In using my device, I so select and regulate the torque developed by the nozzles 38, 40 and the vanes 36 that this torque will exactly counterbalance the precessional torque of the directional gyroscope to which the correcting device is attached. Such regulation may be attained by measuring the precessional torque for the gyroscope in a particular directional gyroscope and then selecting a counteracting torque of known equal magnitude and opposite direction, or by noting the direction of precession, selecting a counteracting torque and then empirically varying its magnitude until precession is halted.

It will be seen that, if the precessional torque is clockwise, as viewed from Fig. 2, the counteracting torque will be supplied by air issuing from the nozzle 40, and, if the precessional torque is counter-clockwise, the counteracting torque will be supplied by air issuing from the nozzle 38.

The value of the counteracting torque can be varied in different ways, for example, by altering the angle at which the streams of air issuing from the nozzles 38, 40 impinge upon the vanes 36. It will be appreciated that this manner of regulation may be effected either by varying the vertical inclination of the nozzles, as viewed from Fig. 1, or by varying the horizontal incline.- tion of the nozzles, as viewed from Fig. 2.

Another and preferable form of means for changing the magnitude and direction of, the counteracting torque is a mechanism for varying the pressure of the air issuing from the nozzles 38, 40 and shutting oil the supply of air from either or both nozzles. Said mechanism comprises a reducing valve 44 intermediate the supply conduit 42 and conduits 46, 48, which connect said supply conduit 42 to the nozzles 38, 40. Said reducing valve is of such type that it can be manipulated to direct air to either nozzle 38, 4D, and to regulate the pressure of air supplied to the selected nozzle.

For this purpose, said valve may comprise a valve body 49 having a cylindrical bore from which extend a radial inlet 50 and two equal radial outlets 52, 54, one on one side and one on the other of said inlet. Said inlet and outlets are connected to the conduits 42, 48, A8, respectively. The valve also includes a cylindrical plug 55 rotatably mounted in the valve body 39. Said plug has a passageway 58 formed in its periphery. This passageway has a portion thereof aligned in all operative positions of the valve with the inlet 53. One end portion 68 of the passageway is adapted to be aligned with the outlet 5:: in one extreme position of the plug, and the other end portion 82 of said passageway is adapted to be aligned with the outlet 52 in the other extreme position of the plug. The angular distance between the two end walls of the passageway 58 is equal to the angular distance between the centers of the two outlets 52, 54 less the angular distance spanned by one of said outlets.

By virtue of this construction, the valve plug 555 can be disposed in what may be called a neutra or oil position in which the passageway 53 is registered with the inlet 59, and has one of its end walls immediately adjacent but out of registration with the outlet 54 and the other of its end Walls immediately adjacent but out of registration with the outlet 52. With the valve in this neutral position, no 'ai will be admitted to either of the nozzles 38, 4!].

If the valve plug is turned in a clockwise direction from neutral position (as viewed in Fig. 1), air will be admitted into the conduit 46 and nozzle 38. The degree to which the valve plug is turned in such clockwise direction will control the pressure of the air flowing into the conduit 85 and the force of the jet emerging from the nozzle 38, so that the further the valve plug is turned in such direction, the greater will be the precessional counteracting torque applied to the sleeve 26. Preferably the outlets 52, 54 and passageway ends 60, G2 are so mutually constructed in a well-known manner that the air pressure will vary linearly with uniform changes in the angular position of the valve plug 56. If the valve plug is turned from neutral in a counter-clockwise direction, air under pressure will be admitted to the conduit 48 and nozzle 48 to apply an opposite precessional counteracting torque.

It will be obvious that by proper manipulation of the valve 44, the proper type and degree of precessional counteracting torque may be applied, and that, if the precessional torque is uniform at all headings of the directional gyroscope, the valve plug may be set in a certain position to counteract this torque. This setting, if desired, can be effected manually.

As indicated earlier, the precessional torque may change with the heading of the directional gyroscope, and to take care of such change, means also can be provided to vary the precessional counteracting torque as a function of the assessemechanism for effecting the foregoing operation may comprise an adjustable cam surface engaging a rider which controls the angular position' of thevalve plug 56, the position of the cam in turn being controlled by the angular position or heading of the gimbal mounting.

More specifically, said mechanism may include a potentiometer resistance coil 66 mounted on the upper wall of the housing I2 concentrically of the sleeve 26'. This coil covers substantially 360". A contact arm 68 securely mounted on the sleeve 25' rides on the resistance coil. Apair' of elec-' trlc leads L, L run from the bell at the terminals It! (the second terminal is hidden in back of the one shown) and an electric lead L" runs from the contact arm at the terminal I2. The angular position of the arm 63 on the coil 66 controls the angular position of a compass deviation ring I4 through any remote control unit will known to the art, such for example as an autosyn unit or potentiometer control system indicated schc inatically by the box IE. The remote control system is such that the angular position of the compass deviation ring '14 closely follows the angular position of the contact arm 58. Thus,

if the arm 68 moves one and one-half degrees counter-clockwise, the compass deviation ring M will turn in a like manner and to a like extent.

Said ring has an annular side wall I? with inwardly extending top and bottom horizontal flanges I8, 80. These flanges are carriedon arms 8| radially emanating from a hub 82, ailixed on the orienting shaft 54 of the remote control unit I6.

The compass deviation ring I4 also includes a resilient strip 86,- which provides the actual cam surface. Said strip is flexed into ap roximately circular configuration and disposed within the ring 14. The strip naturally attempts to return to its original condition and will thus always be biased outwardly, that is, radially away from the shaft 84. The strip is caused to assume its approximately circular configuration by means of a plurality of screws 88 threaded through tapped bores 98 uniformly spaced around the periphery of the annular side wall TI; The tip of each screw has a nib 92 extending therefrom and received in one of a plurality of slots 94 in the strip 86. These slots permit relative shifting of the screw and strip during adjustment of the strip to alter the cam surface which said strip provides. The head of the screw may be formed in any suitable manner as, for example, in a square shape to facilitate handling thereof by a tool, e. g. a wrench. Each screw is also provided with a lock nut 96 to maintain it in adjusted position. The strip is long enough so that its two ends 98, I00 can be trimmed so as to abut each other in any adjusted configuration of the strip.

A circular roller follower I02 is provided to ride upon the cam surface defined by the inner side of the strip 86. This roller is journalled on a shaft I04, carried on one end of a square arm I06, slidably but non-rotatably received in a bearing I08. The other end of the armies is connected to an actuating lever III] by a pair of spaced links H2, pivotally secured to said lever and arm. A pull spring I I6 resiliently forces the roller I02 against the emanating surface 6 or the strip as, The actuatin lever H6 is piv' oted on a shaft H8 and turns a: gear sector I20 in niesh with a gear sector I22 mounted on the valve plug 56.

It will be seen that if the cam surface formed by the strip 86 is irregular, as difierent portions thereof are disposed beneath the roller I02, the valve plug 56 will assume difierent angular positions which are a function of the configuration of said oam surface-and, therefore, of the direction'al gyroscope heading.

In the operation of the device, this cam sur face is so set by proper adjustment of the screws 88 that the valve plug 56, at any given heading of a directional gyroscope, will cause a counteracting precessional torque of the proper magnitude and direction to be applied to the sleeve 26. This may be accomplished as follows: The directional gyroscope is oriented to give 9. def inite heading, for example, north. The valve plug 56 is placed in neutral position and the behavior of the directional gyroscope is observed to see if any precession occurs. If it does, the screw 88 coincident with the radial position of the roller I02 at this time, or the screws to both sides of said roller, is so adjusted that the valve plug 56 will move to a position in which the observed precessional movement of the directional gyroscope is halted. Then a new setting is obtained and the procedure repeated, until every screw 83 has been properly set. Now, the precessional torque of the directional gyroscope at any given heading will always be eounteracted by the torque created by the air jet issuing from one of the nozzles 38, All.

Ordinarily, in a given directional gyroscope, the precessional torque for all headings will either be clockwise or counter-clockwise, but not usually both. However, my improved precession counteracting mechanism wil1 even correct for both types of precessional torques in the same directional gyroscope. If the roller I52 is in a certain radial position relative to the shaft 84, the plug 56 will be in neutral position. If the roller shifts radially outwardly from this position, air will be admitted to the nozzle 38 to provide a clockwise precessionai counteracting torque. On the other hand, if the roller is moved inwardly from its neutral position, air will be admitted to the noz- 21c 40 to impart a counter-clockwise precessional counteracting torque.

It will thus be seen that I have provided a device in which the several objects of the invention are achieved, and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent: H l. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimba1 mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes ona horizontal plane being perpendicular to one another, and means to apply about said vertical arise predetermined torque to said mounting equal in value and opposite in directionto the torque exerted at any given heading by the" directional gyroscope as it tends to precess, said means including a mechanism mounted independently of said gimbal for directing a stream of a fluid medium and means movable with the gimbal and lying in the path of said stream, said last named means being so arranged that when the stream impinges thereon a torque is created about the precessional axis of the rotor.

2. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis andabout a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicular to one another, and means to apply about said vertical axis a. predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a mechanism mounted independently of the gimbal for directing a stream of a fluid medium and means movable with the gimbal and extending completely around the precessional axis of the rotor, said means lying in the path of travel of said stream and said stream moving in such direction that when it impinges on the means carried by the gimbal, said means will create a torque about said precessional axis.

3. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal ax on a horizontal plane being perpendicular to one another, and means to apply about said vertical axis a predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a series of projections and spaces movable with the gimbal and extending completely around the precessional axis of the rotor and a mechanism mounted independently of the gimbal for directing a stream of a fluid medium against said projections in such direction as to create a torque about said precessional axis.

4. A directional gyroscope comprising a. rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicular to one another, and means to apply about said vertical axis a predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a series of closely spaced projections movable with the gimbal and extending completely around the precessional axis of rotation of the rotor and a mechanism mounted independently of the gimbal for directing a stream of a fluid medium against said projections in such direction as to create a torque about said precessional axis.

5. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicularto one another, and means to apply about said vertical axis a predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a series of uniformly and closely spaced projections movable with the gimbal and extending completely around the precessional axis of rotation of the rotor and a mechanism mounted independently of the gimbal for directing a stream of a fluid medium against said projections in such direction as to create a torque about said precessional axis.

} 6. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes ona horizontal plane being perpendicular to one another, and means to apply about said vertical axis a predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a series of uniformly and closely spaced projections movable with the gimbal and extending completely around the precessional axis of rotation of the rotor and a mechanism stationarily mounted independently of the gimbal for directing a stream of a fluid medium against said projections in such direction as to create a torque about said precessional axis.

'7. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicular to one another, and means to apply about said vertical axis a predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a set of uniformly and closely spaced vanes movable with the gimbal and extending radially from the axis of precession of the rotor and completely surrounding said axis, and a mechanism stationarily mounted independently of the gimbal for directing a stream of a fluid medium against said vanes in such direction as to create a torque about said precessional axis.

8. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicular to one another, and means to apply about said vertical axis a predetermined torque to said mounting to the precessional axis of the rotor so that said streams create torques of opposite directions.

9. A directional gyroscope comprising a rotor mounted to spin about a horizontal axis, a gimbal mounting for said rotor, said mounting including a horizontal gimbal ring and a vertical gimbal ring, and means to apply a torque to said vertica1 gimbal ring equal in value'and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a series of uniformly and closely spaced projections movable with the vertical gimbal ring and extending horizontally completely around the vertical axis of rotation of said gimbal and a mechanism stationarily mounted independently of the gimbal for directing a stream of a fluid medium against said projections in such direction as to create a torque about said vertical axis.

10. A directional gyroscopefajs set forth in claim 9 wherein means is provided to vary the value of the predetermined torque opposed to the torque exerted by the directional gyroscope as it tends to precess.

11. A directional gyroscope comprising a rotor mounted to spin about a horizontal axis, means to spin said rotor, a gimbal mounting for the rotor, said mounting including a horizontal gimbal ring and a vertical gimbal ring, and means to apply a predetermined horizontal torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, said means including a series of uniformly, closely spaced projections movable with the vertical imbal ring and extending horizontally, completely around the vertical axis of rotation of said gimbal and a mechanism mounted independently of the gimbal for directing a stream of a fluid medium under pressure against said projections in such direction as to create a torque about said vertical axis.

12. A directional gyroscope as set forth in claim 11 wherein means is provided to vary the pressure of said fluid medium and thereby change the value of the torque opposing the torque exerted by the directional gyroscope as it tends to precess.

13. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicular to one another, means to apply about said vertica1 axis a predetermined torque to said mounting equal in value and opposite in direction-to the torque exerted by the directional gyroscope as it tends to precess, and means to vary said torque with the change in the heading of the directional gyroscope.

14. A directional gyroscope comprising a rotor, means to spin said rotor about a horizontal axis, a gimbal mounting for said rotor including means to permit rotation of the spinning axis of the rotor about a horizontal axis and about a vertical axis, the projections of said horizontal axes on a horizontal plane being perpendicular to one another, means to apply about said vertical axis a predetermined torque to said mounting equal in value and opposite in direction to the torque exerted by the directional gyroscope as it tends to precess, and means to vary said torque with the change in the heading of the directiona1 gyroscope to accord to changes in value of the precessional torque of the directional gyroscope at different headings.

MEYER H. AXLER.

REFERENCES CITED The following references are of record in the file of this patent:

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